Hydraulic pump or motor



June 14, 1949. E. K. BENEDEK HYDRAULIC PUMP OR MOTOR 2 Sheets-Sheet l Filed Sept. 30, 1944 Fig-l INVENTOR F/ek K. Ben edek ATTORNEYS Fatenied June 14, 1949 UNITED STATES PATENT OFFICE HYDRAULIC PUMP R. MOTOR Elek K. Benedek, Chicago, Ill. Application September 30, 1944, Serial No. 556,593

22 Claims. 1

This invention relates to hydraulic pumps or motors, and more particularly to rotary, radial piston and cylinder pumps or motors.

Pumps or motors of this general class are now well known, and have served many and varied purposes very efliciently. variable capacity characteristics make them suitable for use in transmission of power in aircraft propulsion systems but so far as I am aware they have not heretofore been used to any appreciable extent for this purpose. For aircraft use a pump or motor should be light, compact, and capable of operation at extremely high speeds and pressures. A general object of the invention is to provide a pump or motor of the class referred to having novel structural features, relationships, and combinations whereby these and other desirable characteristics are obtained.

Another object of the invention is to provide a pump or motor of the character stated including a new and improved arrangement for transmitting rotative driving efiort between a rotor such as a cylinder barrel, and a rotatable reactance ring or the like.

Another object of the invention is to provide an improved light, compact, and simple reactance ring assembly.

Another object of the invention is to provide, for a pump or motor of the character referred to, an improved pintle so constructed as to combine rigidity and strength with large size of fluid passage area, particularly suction passage area for permitting operation at high speeds.

A further object of the invention is to provide improved means for lubricating a pump of the kind referred to during operation with the parts so adjusted that there is no intake by or pressure discharge from the cylinders. Other objects will become apparent from a reading of the following detailed description, the appended claims, and the accompanying drawings, in which:

Figure 1 is a central, longitudinal sectional view of a pump or motor embodying the invention, the section being taken in a plane perpendicular to the line of shifting of an adjustable eccentric reactance assembly;

Figure 2 is a transverse section on either of the lines 2-2 in Figure 1;

Figure 3 is a fragmentary section on the line 3-3 of Figure 2 with a pintle omitted;

Figure 4 is a fragmentary section on the line 4-4 of Figure 1;

Figure 5 is a fragmentary section on the line 5-5 of Figure 1;

Figure 6 is an enlarged scale fragmentary de- Their smooth flow;

, tion.

The hydraulic apparatus disclosed as embodying the invention in a preferred form is adaptedv to be operated either as a pump or motor. In the rollowing description the cooperation of the parts during pumping operations will be referred to, it being understood that when the apparatus is operated as a motor the cooperation of the parts will be similar, but, in general, in reverse relation.

In its general nature the illustrated apparatus includes a casing A comprising a main or body part I fitted with an end cover 2 which mounts a pintle B in fixed position. A rotor or cylinder barrel C is formed with a bore 3 fitting over the pintle B so as to be rotatable about the pintle axis. The cylinder barrel C is formed with two sets of cylinders t, the respective sets of cylinders being spaced from each other axially of the pintle and eachsset comprising a plurality of radial, circumferentially spaced cylinder members 4. Each cylinder member 4 of one set is disposed in the same radial plane as a companion cylinder member 4 of the other set. The cylinders 4 are formed with ports 5 opening inwardly to the bore 3 so as to have valving cooperation with circumferentially extending low pressure or inlet or suction pintle ports 6 and high pressure or discharge pintle ports 1. Two sets of piston members 8 are mounted respectively for reciprocation in the cylinder members 4 and are operatively connected to a reactance assembly generally designated 9 in a manner to cause reciprocation of the pistons during rotation of the cylinder barrel and also to cause rotation of the reactance assembly 9 concurrently with the cylinder barrel and pistons.

In operation the reactance assembly 9 is positioned eccentrically with respect to the pintle and cylinder barrel axis so that when the cylinder barrel and pistons are rotated the pistons will be reciprocated in the cylinders radially with respect to the. pintle axis. The pintle ports 6 and 1 are so positioned with respect to the eccentricity of the reactance assembly 9 that when the apparatus is operating as a pump the cylinder ports 5 will communicate with the suction ports 6 during the outward strokes of the pistons and will communicate with the discharge ports 1 during the inward strokes of the pistons. As thus far generally described the general organization of parts and mode of operation of the apparatus is similar to those of a number of known prior rotary radial piston and cylinder pumps or motors. The present invention relates more particularly to novel features of construction and relations of parts presently to be described and which achieve the objects previously set forth.

The end cover 2 is formed with a central anchorage or seat H) which provides a fixed mounting for one end of the pintle B as shown in Figure 1. A cap 2 is fitted on the end cover 2 in a manner to provide spaces forming interior ducts H and I2 communicating respectively with fittings I3 and I4 adapted to be connected to suction and discharge conduits (not shown). The suction duct II also communicates with an opening in the pintle which in turn communicates with a bore l6 extending through the pintle and communicating with the suction ports 6 previously referred to. The end cover duct 12 opens into a pintle opening H which leads through two pintle passages l8 to the discharge ports I. In accordance with the invention the cross sectional area of the suction passage bore I6 is much greater than the aggregate cross sectional area of the discharge passages l8 and preferably the diameter of the suction passage 16 is greater than one-half the diameter, i. e., is greater than the radius, of the pintle. The very large suction passage l6 provides for relatively slow velocity flow of the fluid being sucked into the cylinders and thereby minimizes the danger of the pistons running ahead of the supply of fluid and causing partial evacuation of the suction passages at high pump speeds. Theoretically, it would be advantageous, insofar as fluid flow considerations alone are concerned, to make the suction passage 16 even larger than shown. However, it has been found that the size of the passage 16 illustrated is the most practical and advantageous size compatible with strength and rigidity of the pintle.

The discharge passages 18 extending through the pintle need not provide so great an aggregate cross sectional area for fluid flow as the suction passage 16 because the fluid is forced through the passages l8 under positive pressure. Of course, the passages 18 must be large enough to keep the fluid velocity low enough to avoid inordinate friction loss but oher than this consideration the passages 18 may be quite small in order that the suction passage l6 may dominate the pintle cross section.

In order to make possible the formation of a very large suction passage in the pintle without substantial loss of rigidity, the pintle is formed with novel reinforcing means which, in the form shown, includes two oppositely disposed bridges Ill-l9 and two other oppositely disposed bridges 20-20 angularly spaced ninety degrees from the bridges l9-l9. The bridges l9-l9 are located in a median plane of the pintle and serve not only to reinforce the pintle in the zones of the ports 6 and 'l, but also as valve elements separating the cylinders on the suction side of the pump from the cylinders on the discharge side. For properly performing their valving function and for giving added stiffness and strength to the pintle, the bridges l9|9 are of relatively great circumferential extent and preferably should be somewhat wider circumferentially than the cylinder ports 5.

The bridges 20 are located respectively in the middle of the suction and pressure period sides of the pintle and are of considerably less circumferential extent than the cylinder ports 5, so that they do not seriously interfere with flow of fluid through the ports 5 during the suction and discharge strokes of the pistons 8. The bridges l9 and 20, located and relatively proportioned in size as shown in Figure 2, make it possible to form the suction passage IS with a very large cross sectional area and at the same time rigidity of the pintle is maintained.

Referring in more detail to the mounting and driving of the cylinder barrel C, the bore 3 fits the pintle snugly with a close running fit and with only a small clearance through'whlch there can be a limited fluid slip under high pressure. The end of the cylinder barrel adjacent the free end of the pintle is mounted on roller bearings 2| surrounding the pintle and held against axial movement by a sleeve 22 fast in a cylinder barrel extension 23. The interior of the sleeve 22 is splined to receive the splined inner end 24 of a coupling 25 having a reduced section 26 and a splined outer end 21 adapted to be connected to an engine, motor, or the like, preferably through a universal coupling (not shown). If the pump encounters an abnormal overload condition or if there should be some other unusual restraint upon rotation of the cylinder barrel C, the reduced coupling section 26 will fall under torsion so as to avoid damaging the pump.

The cylinder barrel extension 23 is journaled in the right hand end of the casing A by a ball bearing assembly 28, the inner race 29 of which is held against a shoulder 30 by a retainer ring 3|. The bearing outer race is held against a casing shoulder 32 by a ring nut 33 which is recessed to accommodate a packing 34 acting to seal the casing against the escape of fluid which may slip into the region radially beyond the cylinder barrel C.

The reactance ring assembly 9 comprises two end members 35 clamped toward each other by bolts 36 or other suitable fasteners but held apart and spaced axially of the pintle by circumferentially deployed sleeves 31 through which the bolts 36 extend. The members 35 are formed with flanges 38 which extend axially towards each other, the inner faces of the flanges providing outer tracks which face inwardly towards the axis of rotation. The outer tracks provided by the flanges 38 also act as stops for limiting outward radial movement of the sleeves 31 when assembling the members 35, bolts 36, and the spacing sleeves. When all of the sleeves 31 engage the outer tracks the members 35 will be aligned concentrically.

The spacing sleeves 31 also position an outer central reactance ring part 39 concentrically with respect to the end members 35. Two axially spaced inner ring parts 40 located respectively in the zones of the flanges 38 engage the spacers 31 which position the rings 40 concentrically with respect to the flanges 38. The rings 40 are formed with smooth annular surfaces which face outwardly from the axis of rotation to provide innor reactance tracks. A thin annular band 4| seated in appropriate recesses in the end members 35 closes the gaps between the central ring member 39 and the end members 35.

The end members 35 are provided respectively with axial projections or extensions 42 formed with seats for inner races '43 of ball bearing assemblies 44. The races 43 are held in place by retainers 45. The outer races 46 of the bearing assemblies 44 are held in shiftable rings 41 by retainers 48. The rings 41 are formed respectively with pads 49 mounted to slide on fixed casing pads 50 so as to enable the reactance assembly 39 to be shifted from a position of concentricity with respect to the pintle to selected eccentric positions.

The reactance assembly is urged to one eccentric position (to the left as viewed in Figures 2 and 3) by two springs acting on the shiftable rings 41, one of the springs being shown at 5| in Figure 3 as being housed in a cup mounting 52 secured to the casing A. The action of the springs 5| urging the reactance assembly to an eccentric position may be opposed under suitable control by means of fluid pressure responsive means preferably actingat both ends of the reactance assembly, one such means being shown in Figure 3 as including a plunger or piston 53 operable in a cylinder 54 adapted to be connected at 55 to a source of controlled fluid pressure. In order to set the pump for maximum volumetric capacity, pressure is relieved in the cylinders 54 so as to permit the springs 55 to shift the reactance assembly to its position of maximum eccentricity. In order to decrease the volumetric capacity, pressure fluid is admitted into the cylinders 54 thereby forcing the plungers 53 and shifting the reactance assembly against the urge of the springs 5| so as to decrease the eccentricity of the reactance assembly with respect to the pintle.

Means for transmitting radial thrust is interposed between each pair of adjacent pistons 8-8 and the reactance ring assembly. Each piston is formed with a head 56 which is bored to receive a bushing 51. A single thrust transmitting roller 58 passes through the bushings 51-51 of two adjacent piston heads and engages the outer tracks provided by the flanges 38 and the central ring part 39, and the inner track members 40. In operation, when the reactance assembly is eccentric to the pintle axis, rotation of the cylinder barrel and pistons will cause the rollers 58 to be reciprocated by their engagement with the eccentric outer and inner tracks,

In accordance with the invention the pistons 8 are resiliently connected to the reactance ring so as to cause concurrent rotation of the reactance ring, the pistons, and the cylinder barrel without its being necessary for the rollers 58 to rotate the reactance assembly by their thrust transmitting engagement with the reactance tracks. The resilient connections referred to include for each pair of adjacent pistons 8-8 a pin 59 connected to the pistons and extending freely into arcuate slots 60 in the reactance end members 35. The pins 59 may move in the slots 60 circumferentially with respect to the reactance axis, but such movement is limited by engagement of the pin ends with the ends of the slots 60 so that relative rotative movement between the piston and cylinder assemblies and the reactance assembly is held to a minimum. This desirably reduces the Wear on the rollers 58 and the reactance tracks 38, 39 and 40.

In order to eliminate shocks which would occur if the pins 59 were brought abruptly into rigid rotation-transmitting connection with the ends of the slots 60, the pins are so constructed and so mounted as to be yieldable in the manner. of a cantilever beam. In the form shown the pins 59 are formed as resilient bar spring elements centrally mounted as at 6| in the rollers 56, the free end portions of the pins projecting through clearances 62 which extend inwardly from both ends of the rollers 58. The

clearance spaces 62 provide freedom for the pinsv 59 to yield or deflect clrcumferentially of the reactance ring 9 when the pin ends engage the ends of the slots 60, thus absorbing shocks while still emciently transmitting rotative driving! efiort between the pistons and the reactance assembly.

In normal operation, when the cylinder barrel is rotating and the. pistons are reciprocating, fluid under high pressure will slip constantly into the clearance space between the pintle and the barrel bore 3 so as to maintain the pintle and cylinder barrel lubricated, some of the slip fluid passing beyond the right hand end of the pintle to lubricate the roller bearings 20. However, if the reactance assembly is positioned concentrically the pistons 8 will not reciprocate and nohigh pressure fluid will be forced from the cylinders into the slip fluid clearance space. In accordance with the invention means are provided for maintaining the pump efficiently lubricated when the cylinder barrel and associated parts are being rotated but with the reactance assembly in concentric or neutral position. A slip fluid-receiving-chamber or space 63 is provided at the free end of the pintle, being defined by the pintle end, the inside of the sleeve 22, which rotates with and in elfect is part of the cylinder barrel, and an end closure 64. During normal operation, with the pistons reciprocating, slip fluid will accumulate in the chamber 63 and if the reciprocation of the pistons then is stopped while the cylinder barrel continues to rotate, the body of fluid in the chamber 63 will be under pressure created by centrifugal force due to its rotation with the cylinder barrel. This pressure will be suflicient to force the fluid from the chamber 63 back past the roller bearings 20 and into the clearance between the pintle and the cylinder barrel bore 3. In this way the slip fluid accumulated in the space 63 will lubricate the parts for a limited period. If conditions require that the pump continue to rotate for a substantial time under no-discharge conditions, the accumulated slip fluid in the chamber 63 ultimately .would become exhausted, lubrication would be discontinued, and damage to the parts would result. To prevent this, the slip fluid receiving space 63 is connected by a pipe 65 to a reservoir 66 of large capacity. Conveniently, the pipe 65, which may be rather small, passes through the large suction passage I6.

When the pump discharges fluid under pressure for a sustained period, slip fluid will fill the receiving space 63 and then the excess fluid will pass through the pipe 65 into the reservoir 66. If now the reactance assembly is set concentrically with respect to the pintle the slip fluid in the space 63 will work back into the bearings 20 and clearance between the pintle and cylinder barrel bore, the fluid thus removed from the space 63 being constantly replaced by fluid drawn back from the reservoir 66 through the pipe 65. The period during which the pump can be lubricated efliciently while the cylinder barrel is rotating but without pumping fluid under pressure is limited only by the capacity of the exterior reservoir 66.

The pump or motor disclosed by way of example embodies the invention in a preferred form but it will be apparent that changes may be made in the construction and relative arrangement of the illustrated parts without departing from the invention as defined in the claims.

I claim:

1. In a rotary radial piston and cylinder pump or motor, a rotor; reactance means including a rotatable reactance ring and means mounting said reactance ring to rotate about an axis eccentric to the axis of rotation of said rotor; a set of radial cylinder members; a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor; and connections between the individual reciprocable members and said reactance ring comprising roller means for transmitting radial thrust between the reactance ring and the reciprocable member and a pin and slot connection for rotating said reactance ring in response to rotation of said rotor and said cylinder and piston members, the slot of said pin and slot connections having closed ends engageable by the pin of said pin and slot connection and extending arcuately and concentrically with respect to said reactance ring.

2. In a rotary radial piston and cylinder pump or motor, a rotor; reactance means including a rotatable reactance ring and means mounting said reactance ring to rotate about an axis ec centric to the axis of rotation of said rotor; a set of radial cylinder members; a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor; and connections between the individual reciprocable members and said reactance ring comprising roller means for transmitting radial thrust between the reactance ring and the reciprocable member and resilient means operatively interposed between and connecting said ring and said rotor for concurrent rotation and being yieldable tangentially with respect to a circle concentric with said ring.

3. In a rotary radial piston and cylinder pump or motor, a rotor; reactance means including a rotatable reactance ring and means mounting said reactance ring to rotate about an axis eccentric to the axis of rotation of said rotor; a set of radial cylinder members; a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor; and connections between the individual reciprocable members and said reactance ring comprising roller means for transmitting radial thrust between the reactance ring and the reciprocable member and a pin and slot connection for rotating said reactance ring in response to rotation of said rotor and said cylinder and piston members, the slot of said pin and slot connection extending arcuately and concentrically with respect to said reactance ring, the pin of Said pin and slot connection extending parallel to the axis of said reactance ring and being mounted as a cantilever beam with its unsupported end portion extending freely into said slot.

4. In a rotary radial piston and cylinder pump or motor, a rotor; reactance means includin a rotatable reactance ring and means mounting said reactance ring to rotate about an axis eccentric to the axis of rotation of said rotor; a set of radial cylinder members; a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor; and connections between the individual reciprocable members and said reactance ring comprising roller means for transmitting radial thrust between the reactance ring and the reciprocable member and a pin and slot connection for rotating said reactance ring in response to rotation of said rotor and said cylinder and piston members, the slot of said pin and slot connection being formed in said reactance ring and extending arcuately and concentrically with respect to said ring, and the pin of said pin and slot connection extending parallel to the reactance ring axis and being mounted on the reciprocable member as a cantilever beam with its unsupported end extending freely into said slot.

5. In a rotary radial piston and cylinder pump or motor, a rotor; reactance means including a rotatable reactance ring and means mounting said reactance ring to rotate about an axis eccentric to the axis of rotation of said rotor; a set of radial cylinder members; a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor; and connections between the individual reciprocable members and said reactance ring comprising circumferential tracks on said reactance ring respectively on opposite sides of said reciprocable member, a thrust transmitting roller journaled on said reciprocable member and having its opposite ends engaging said tracks respectively, clearance spaces extending axially and inwardly from the opposite ends of said roller toward the center thereof, arcuate slots in said ring respectively on opposite sides of said reciprocable member and concentric with said tracks, and a flexible pin extending through said roller and being mounted on said roller adjacent the center thereof, the opposite end portions of said pin projecting through said clearance spaces out of contact with said roller and freely into said slots.

6. In a rotary radial piston and cylinder pump or motor, a rotor; reactance means including a rotatable reactance ring and means mounting said reactance ring to rotate about an axis eccentric to'the axis of rotation of said rotor; a set of radial cylinder members; a set oi cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor; and connections between the individual reciprocable members and said reactance ring comprising circumferential tracks on said reactance ring respectively on opposite sides of said reciprocable member, a thrust transmitting roller journaled on said reciprocable member and having its opposite ends engaging said tracks respectively, clearance spaces extending axially and inwardly from the opposite ends of said roller toward the center thereof, arcuate slots in said ring respectively On opposite sides of said reciprocable member and concentric with said tracks, and a bar spring extending through said roller and being mounted on said roller adjacent the center thereof to provide two cantilever end portions projecting through said clearance spaces and freely into said slots, said spaces providing suflicient clearance between said bar spring cantilever portions and said roller to enable said cantilever portions-to be deflected circumferentially to thus absorb shocks in the transmission of rotative driving effort between said rotor and said reactance ring.

7. In a rotary radial piston and cylinder pump or motor; a rotor; reactance means including a rotatable reactance ring and means mounting said ring to rotate about an axis eccentric to the axis of rotation of said rotor; a set of radial cylinder members; and a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor, said reactance means comprising two opposed end members, spacers interposed between said end members for holding them spaced from each other axially of said rotor, stops on said end members for limiting outward radial movement of said spacers, fasteners for drawing said end members towards each other and against said spacers, and an annular central reactance part between said end members and spaced axially from both end members and being located radially by engagement with said spacers.

8. In a rotary radial piston and cylinder pump or motor; a rotor; reactance means including a rotatable reactance ring and means mounting said ring to rotate about an axis eccentric to the axis of rotation of said rotator; a set of radial cylinder members; and a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor, said reactance means comprising two opposed end members, spacer sleeves interposed between said end members for holding them spaced from each other axially of said rotor, stops on said end members for limiting outward radial movement of said spacer sleeves, bolts extending through said spacer sleeves for drawing said end members towards each other and against said spacer sleeves, and an annular central reactance part between said end members and spaced axially from both end members and being located radially by engagement with said spacer sleeves.

' 9. In a rotary radial piston and cylinder pump or motor; a rotor; reactance means including a rotatable reactance ring and means mounting said ring to rotate about an axis eccentric to the axis of rotation of said rotor; a set of radial cylinder members; and a set of cooperating piston members, one of said sets being on and rotatable with said rotor and the other of said sets being operatively connected to said reactance ring for being reciprocated relatively to the respectively associated members of said other set during concurrent rotation of said ring and said rotor, said reactance means comprising two opposed end members formed respectively with circumferential flanges extending towards each other, a plurality of circumferentially deployed spacers interposed between said end members and being insertable radially and outwardly between said end members and into engagement with said flanges, an annular central reactance part axially between said end members and'being located concentrically with respect to said end members by engagement with said spacers, and fasteners for drawing said end members towards each other and against said spacers.

10. In a rotary radial piston and cylinder pump or motor, a casing; a pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality or radially disposed circumferentially spaced cylinders in said barrel; pistons reciprocable respectively in said cylinders; a reactance ring assembly surrounding said pistons and cylinders; means mounting said assembly to rotate eccentrically with respect to the pintle axis, said assembly comprising two axially spaced opposed end members formed respectively with circumferential flanges extending towards each other to provide axially spaced outer tracks facing towards said pintle axis, a plurality of circumferentially deployed spacer sleeves interposed endwise between said end members and engaging said outer tracks, two inner track members respectively adjacent said end members and having inner tracks facing away'from said pintle axis and being engaged by said spacer sleeves whereby said inner tracks are held concentric with said outer tracks, and bolts extending respectively through said spacer sleeves for clamping said end members against said spacer sleeves; and thrust transmitting rollers journaled in said pistons respectively and having their opposite end portions extending between the inner and outer tracks.

11. In a rotary radial piston and cylinder pump or motor, a casing; a pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality of radially disposed circumferentially spaced cylinders in said barrel; pistons reciprocable respectively in said cylinders; a reactance ring assembly surrounding said pistons and cyl-' inders; means mounting said assembly to rotate eccentrically with respect to the pintle axis, said assembly comprising two axially spaced opposed end members formed respectively with circumferential flanges extending towards each other to provide axially spaced outer tracks facing towards said pintle axis, a plurality of eircumferentially deployed spacer sleeves interposed endwise between said end members and engaging said outer tracks, two inner track members respectively adjacent said end members and having inner tracks facing away from said pintle axis and being enaged by said spacer sleeves whereby said inner tracks are held concentric with said outer tracks, and bolts extending respectively through said spacer sleeves for clamping said end members against said spacer sleeves; thrust transmitting rollers journaled in said pistons respectively and having their opposite end portions extending between the inner and outer tracks; and means flexibly connecting said pistons and said reactance ring assembly to rotate concurrently comprising a plurality of slots in said end members extending arcuately and concentrically with respect to the axis of said assembly; and pins extending through said rollers with their ends projecting into said slots; said pins having their central portions anchored within the associated rollers and having end portions free to deflect within the end portions of said rollers.

12. A reactance ring assembly for a rotary radial piston and cylinder pump or motor comprising two opposed end members, spacers interposed between said end members for holding them spaced from each other axially of said rotor, stops on said end members for limiting outward radial movement of said spacers, fasteners for drawing said end members towards each other and against said spacers, and an annular central reactance part between said end members and spaced axially from both end members and being located radially by engagement with said spacers.

13. A reactance ring assembly for a rotary radial piston and cylinder pump or motor comprising two opposed end members formed respectively with circumferential flanges extending towards each other, a plurality of circumferentially deployed spacers interposed between said end members and being insertable radially and outwardly between said end members and into engagement with said flanges. an annular central reactance part axially between said end members and being located concentrically with respect to said end members by engagement with said spacers, and fasteners for drawing said end members towards each other and against said, spacers.

14. A reactance ring assembly for a rotary radial piston and cylinder pump or motor comprising two axially spaced opposed end members formed respectively with circumferential flanges extending towards each other to provide axially spaced outer tracks facing towards the axis of the ring assembly, a plurality of circumferentially deployed spacer sleeves interposed between said end members and engaging said outer tracks, two inner track members respectively adjacent said end members and having inner tracks facing away from said axis and being engaged by said spacer sleeves whereby said inner tracks are held concentric with said outer tracks, and bolts extending respectively through said spacer sleeves for clamping said end members against said spacer sleeves.

15. In a rotary radial piston and cylinder pump or motor, a casing; a stationary pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality of radial, circumferentially spaced cylinders in said cylinder barrel; pistons reciprocable in said cylinders respectively; means for reciprocating said pistons in response to rotation of said cylinder barrel; ports opening inwardly from said cylinders toward said pintle; circumferentially extending suction and discharge ports respectively on opposite sides of a median plane of said pintle adapted to register with said cylinder ports; suction passage means extending longitudinally through said pintle and communicating with said suction port; and discharge passage means extending longitudinally through said pintle and communicating with said discharge port, the cross sectional area of said suction passage means being much greater than the cross sectional area of said discharge passage means.

16. In a rotary radial piston and cylinder pump or motor, a casing; a stationary pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality of radial, circumferentially spaced cylinders in said cylinder barrel; pistons reciprocable in said cylinders respectively; means for reciprocating said pistons in response to rotation of said cylinder barrel; ports opening inwardly from said cylinders toward said pintle; two bridge portions of relatively great circumferential extent on opposite sides of said pintle; two bridge portions of relatively small circumferential extent on opposite sides of said pintle and spaced substantially ninety degrees from said first named bridge portions; suction ports in said pintle respectively extending circumferentially between one of said bridge portions of relatively small circumferential extent and said two bridge portions of relatively great circumferential extent; and discharge ports in said pintle respectively extending circumferentially between the other of said bridge portions of relatively small circumferential extent and said two bridge portions of relatively great circumferential extent.

17. In a rotary radial piston and cylinder pump or motor, a casing; a stationary pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality of radial, circumferentially spaced cylinders in said cylinder barrel; pistons reciprocable in said cylinders respectively; means for reciprocating said pistons in response to rotation of said cylinder barrel; ports opening inwardly from said cylinders toward said pintle; two bridge portions of relatively great circumferential extent on opposite sides of said pintle; two bridge portions of relatively small circumferential extent on opposite sides of said pintle and spaced substantially ninety degrees from said first named bridge portions; suction ports in said pintle respectively extending circumferentially between one of said bridge portions of relatively small circumferential extent" and said two bridge portions of relatively great circumferential extent; discharge ports in said pintle respectively extending circumferentially between the other of said bridge portions of relatively small circumferential extent and said two bridge portions of relatively great circumferential extent; suction passage means extending longitudinally through said pintle and communicating with said suction port; and discharge passage means extending longitudinally through said pintle and communicating with said discharge port, the cross sectional area of said suction passage means being much greater than the cross sectional area of said discharge passage means.

18. In a rotary radial piston and cylinder pump or motor, a casing; a stationary pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality of radial, circumferentially spaced cylinders in said cylinder barrel; pistons reciprocable in said cylinders respectively; means for reciprocating said pistons in response to rotation of said cylinder barrel; ports opening inwardly from said cylinder toward said pintle; circumferentially extending suction and discharge ports respectively on opposite sides of a median plane of said pintle adapted to register with said cylinder ports; a suction passage of diameter greater than the radius of said pintle extending longitudinally through said pintle and communicating with said suction port; and discharge passage means extending longitudinally through said pintle and communicating with said discharge port.

19. In a rotary radial piston and cylinder pump or motor, a casing; a stationary pintle mounted in said casing; a cylinder barrel rotatable about said pintle; a plurality of radial, circumferentially spaced cylinders in said cylinder barrel; pistons reciprocable in said cylinders respectively; means for reciprocating said pistons in re- 13 sponse to rotation of said cylinder barrel; ports opening inwardly from said cylinders toward said pintle; two bridge portions'oi' relatively great circumferential extent on opposite sides of said pintle; two bridge portions of relatively small circumferential extent on opposite sides of said pintle and spaced substantially ninety degrees from said first named bridge portions; suction ports in said pintle respectively extending cir cumferentially between one of said bridge portions of relatively small circumferential extent' and said two bridge portions of relatively great circumferential extent; discharge ports in said pintle respectively extending circumferentially between the other of said bridge portions of relatively small circumferential extent and said two bridge portions of relatively great circumferential extent a suction passage of a diameter at least as great as the radius of said pintle extending longitudinally through said pintle and communicating with said suction ports; and discharge passage means extending longitudinally through said pintle and communicating with said discharge rts. 20. In a rotary radial piston and cylinder pump or motor, a stationary pintle; a cylinder barrel mounted to rotate about said pintle and having a bore in which the pintle is fitted with a clearance sufllcient to permit restricted slip of fluid under working pressure; a slip-fluid-receiving space communicating with said clearance and being defined at least in part by an end of said pintle and said cylinder barrel; radial cylinders in said cylinder barrel; ports opening from said K cylinders into said barrel bore; inlet and discharge ports in said pintle adapted to have valving communication with said cylinder ports; a reservoir; and a conduit-leading from said slip-- fluid-receiving space to said reservoir, said conduit and reservoir being adapted to relieve the slip-fluid-receiving space of fluid which has 14 pintle, out of communication with said cylinder and pintle ports, and to said reservoir, said conduit and reservoir being adapted to relieve the.

slip-fluid-receiving space of fluid which has slipped through said clearance under working pressure in amount in excess of the capacity of said slip-fluid-receiving space and being adapted to maintain said slip-fluid-receiving space full of fluid when the fluid is not working under pressure in the cylinders, whereby there will be maintained in said receiving space at all times a quantity of fluid rotating with said cylinder barrel and under resultant centrifugaily generated pressure for forcing fluid from said slip-fluid-recelving space into said clearance oppositely to the direction of working pressure fluid slip.

22. In a rotary pump or motor, a casing comprising a body part open at one end, and an end cover fitted in said open end to be removable therefrom a pintle mounted at one of its ends on said end cover and projecting toward the other slipped through said clearance under working pressure in amount in excess of the capacity of said slip-fluid-receiving space and being adapted to maintain said slip-fluid-receiving space full of fluid when the fluid is not working under pressure in the cylinders, whereby there-will be maintained in said receiving space at all times a quantity of fluid rotating with said cylinder barrel and under resultant centrifugally generated pressure for forcing fluid from said slip-fluid-receiving space into said clearance oppositely to-the direction of working pressure fluid slip.

21. In a rotary radial piston and cylinder pump or motor, a stationary pintle; a cylinder barrel mounted to rotate about said pintle and having a bore in which the pintle is fltted with a clearance suflicient to permit restricted slip of fluid under working pressure; a slip-fluid-receiving space communicating with said clearance and being defined at least in part by an end of said pintle and said cylinder barrel; ports opening from said cylinders into said barrel bore; inlet and discharge ports in said pintle adapted to have valving communication with said cylinder ports; a reservoir; and a conduit leading from said slipiluid-receiving space longitudinally through said end of said casing body part; a cylinder barrel mounted in said casing body part for rotation about said pintle; a reactance structure mounted within said casing body part in surrounding relation to said cylinder barrel; 'a plurality of rotatable radial piston and cylinder assemblies of which the pistons are reciprocable relatively to the cylinders in response to rotation of said cylinder barrel, said end cover and said pintle being removable from the pump or motor assembly as a unit without disturbing the mounting of said reactance structure. and said cylinder barrel in said casing body part, an opening through said other end of said casing body part coaxial with said cylinder barrel; a journal extending axially from said cylinder barrel through said opening; an anti-friction bearing assembly in said opening and including an inner race surrounding and fltted to said journal and an outer race fitted within the wall of said opening; mutually engaging means on the casing body part and the outer race for limiting movement of said outer race and hence said bearing assembly axially towards said open end of said casing body part; and a ring detachably secured to said casing body part and abutting said outer race for holding said outer race and hence said bearing assembly against movement axially away from said open end of said casing body part.

' ELEK K. BENEDEK.

. annnnnncns crrnn .The following references are of record in the Carter Jan. 7,' 1941 

